ndisc.c revision bea851954717ebb0dee557a951e28bb277e1cc1d
1/* 2 * Neighbour Discovery for IPv6 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * Mike Shaver <shaver@ingenia.com> 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 */ 14 15/* 16 * Changes: 17 * 18 * Pierre Ynard : export userland ND options 19 * through netlink (RDNSS support) 20 * Lars Fenneberg : fixed MTU setting on receipt 21 * of an RA. 22 * Janos Farkas : kmalloc failure checks 23 * Alexey Kuznetsov : state machine reworked 24 * and moved to net/core. 25 * Pekka Savola : RFC2461 validation 26 * YOSHIFUJI Hideaki @USAGI : Verify ND options properly 27 */ 28 29/* Set to 3 to get tracing... */ 30#define ND_DEBUG 1 31 32#define ND_PRINTK(fmt, args...) do { if (net_ratelimit()) { printk(fmt, ## args); } } while(0) 33#define ND_NOPRINTK(x...) do { ; } while(0) 34#define ND_PRINTK0 ND_PRINTK 35#define ND_PRINTK1 ND_NOPRINTK 36#define ND_PRINTK2 ND_NOPRINTK 37#define ND_PRINTK3 ND_NOPRINTK 38#if ND_DEBUG >= 1 39#undef ND_PRINTK1 40#define ND_PRINTK1 ND_PRINTK 41#endif 42#if ND_DEBUG >= 2 43#undef ND_PRINTK2 44#define ND_PRINTK2 ND_PRINTK 45#endif 46#if ND_DEBUG >= 3 47#undef ND_PRINTK3 48#define ND_PRINTK3 ND_PRINTK 49#endif 50 51#include <linux/module.h> 52#include <linux/errno.h> 53#include <linux/types.h> 54#include <linux/socket.h> 55#include <linux/sockios.h> 56#include <linux/sched.h> 57#include <linux/net.h> 58#include <linux/in6.h> 59#include <linux/route.h> 60#include <linux/init.h> 61#include <linux/rcupdate.h> 62#ifdef CONFIG_SYSCTL 63#include <linux/sysctl.h> 64#endif 65 66#include <linux/if_addr.h> 67#include <linux/if_arp.h> 68#include <linux/ipv6.h> 69#include <linux/icmpv6.h> 70#include <linux/jhash.h> 71 72#include <net/sock.h> 73#include <net/snmp.h> 74 75#include <net/ipv6.h> 76#include <net/protocol.h> 77#include <net/ndisc.h> 78#include <net/ip6_route.h> 79#include <net/addrconf.h> 80#include <net/icmp.h> 81 82#include <net/netlink.h> 83#include <linux/rtnetlink.h> 84 85#include <net/flow.h> 86#include <net/ip6_checksum.h> 87#include <linux/proc_fs.h> 88 89#include <linux/netfilter.h> 90#include <linux/netfilter_ipv6.h> 91 92static struct socket *ndisc_socket; 93 94static u32 ndisc_hash(const void *pkey, const struct net_device *dev); 95static int ndisc_constructor(struct neighbour *neigh); 96static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb); 97static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb); 98static int pndisc_constructor(struct pneigh_entry *n); 99static void pndisc_destructor(struct pneigh_entry *n); 100static void pndisc_redo(struct sk_buff *skb); 101 102static struct neigh_ops ndisc_generic_ops = { 103 .family = AF_INET6, 104 .solicit = ndisc_solicit, 105 .error_report = ndisc_error_report, 106 .output = neigh_resolve_output, 107 .connected_output = neigh_connected_output, 108 .hh_output = dev_queue_xmit, 109 .queue_xmit = dev_queue_xmit, 110}; 111 112static struct neigh_ops ndisc_hh_ops = { 113 .family = AF_INET6, 114 .solicit = ndisc_solicit, 115 .error_report = ndisc_error_report, 116 .output = neigh_resolve_output, 117 .connected_output = neigh_resolve_output, 118 .hh_output = dev_queue_xmit, 119 .queue_xmit = dev_queue_xmit, 120}; 121 122 123static struct neigh_ops ndisc_direct_ops = { 124 .family = AF_INET6, 125 .output = dev_queue_xmit, 126 .connected_output = dev_queue_xmit, 127 .hh_output = dev_queue_xmit, 128 .queue_xmit = dev_queue_xmit, 129}; 130 131struct neigh_table nd_tbl = { 132 .family = AF_INET6, 133 .entry_size = sizeof(struct neighbour) + sizeof(struct in6_addr), 134 .key_len = sizeof(struct in6_addr), 135 .hash = ndisc_hash, 136 .constructor = ndisc_constructor, 137 .pconstructor = pndisc_constructor, 138 .pdestructor = pndisc_destructor, 139 .proxy_redo = pndisc_redo, 140 .id = "ndisc_cache", 141 .parms = { 142 .tbl = &nd_tbl, 143 .base_reachable_time = 30 * HZ, 144 .retrans_time = 1 * HZ, 145 .gc_staletime = 60 * HZ, 146 .reachable_time = 30 * HZ, 147 .delay_probe_time = 5 * HZ, 148 .queue_len = 3, 149 .ucast_probes = 3, 150 .mcast_probes = 3, 151 .anycast_delay = 1 * HZ, 152 .proxy_delay = (8 * HZ) / 10, 153 .proxy_qlen = 64, 154 }, 155 .gc_interval = 30 * HZ, 156 .gc_thresh1 = 128, 157 .gc_thresh2 = 512, 158 .gc_thresh3 = 1024, 159}; 160 161/* ND options */ 162struct ndisc_options { 163 struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX]; 164#ifdef CONFIG_IPV6_ROUTE_INFO 165 struct nd_opt_hdr *nd_opts_ri; 166 struct nd_opt_hdr *nd_opts_ri_end; 167#endif 168 struct nd_opt_hdr *nd_useropts; 169 struct nd_opt_hdr *nd_useropts_end; 170}; 171 172#define nd_opts_src_lladdr nd_opt_array[ND_OPT_SOURCE_LL_ADDR] 173#define nd_opts_tgt_lladdr nd_opt_array[ND_OPT_TARGET_LL_ADDR] 174#define nd_opts_pi nd_opt_array[ND_OPT_PREFIX_INFO] 175#define nd_opts_pi_end nd_opt_array[__ND_OPT_PREFIX_INFO_END] 176#define nd_opts_rh nd_opt_array[ND_OPT_REDIRECT_HDR] 177#define nd_opts_mtu nd_opt_array[ND_OPT_MTU] 178 179#define NDISC_OPT_SPACE(len) (((len)+2+7)&~7) 180 181/* 182 * Return the padding between the option length and the start of the 183 * link addr. Currently only IP-over-InfiniBand needs this, although 184 * if RFC 3831 IPv6-over-Fibre Channel is ever implemented it may 185 * also need a pad of 2. 186 */ 187static int ndisc_addr_option_pad(unsigned short type) 188{ 189 switch (type) { 190 case ARPHRD_INFINIBAND: return 2; 191 default: return 0; 192 } 193} 194 195static inline int ndisc_opt_addr_space(struct net_device *dev) 196{ 197 return NDISC_OPT_SPACE(dev->addr_len + ndisc_addr_option_pad(dev->type)); 198} 199 200static u8 *ndisc_fill_addr_option(u8 *opt, int type, void *data, int data_len, 201 unsigned short addr_type) 202{ 203 int space = NDISC_OPT_SPACE(data_len); 204 int pad = ndisc_addr_option_pad(addr_type); 205 206 opt[0] = type; 207 opt[1] = space>>3; 208 209 memset(opt + 2, 0, pad); 210 opt += pad; 211 space -= pad; 212 213 memcpy(opt+2, data, data_len); 214 data_len += 2; 215 opt += data_len; 216 if ((space -= data_len) > 0) 217 memset(opt, 0, space); 218 return opt + space; 219} 220 221static struct nd_opt_hdr *ndisc_next_option(struct nd_opt_hdr *cur, 222 struct nd_opt_hdr *end) 223{ 224 int type; 225 if (!cur || !end || cur >= end) 226 return NULL; 227 type = cur->nd_opt_type; 228 do { 229 cur = ((void *)cur) + (cur->nd_opt_len << 3); 230 } while(cur < end && cur->nd_opt_type != type); 231 return (cur <= end && cur->nd_opt_type == type ? cur : NULL); 232} 233 234static inline int ndisc_is_useropt(struct nd_opt_hdr *opt) 235{ 236 return (opt->nd_opt_type == ND_OPT_RDNSS); 237} 238 239static struct nd_opt_hdr *ndisc_next_useropt(struct nd_opt_hdr *cur, 240 struct nd_opt_hdr *end) 241{ 242 if (!cur || !end || cur >= end) 243 return NULL; 244 do { 245 cur = ((void *)cur) + (cur->nd_opt_len << 3); 246 } while(cur < end && !ndisc_is_useropt(cur)); 247 return (cur <= end && ndisc_is_useropt(cur) ? cur : NULL); 248} 249 250static struct ndisc_options *ndisc_parse_options(u8 *opt, int opt_len, 251 struct ndisc_options *ndopts) 252{ 253 struct nd_opt_hdr *nd_opt = (struct nd_opt_hdr *)opt; 254 255 if (!nd_opt || opt_len < 0 || !ndopts) 256 return NULL; 257 memset(ndopts, 0, sizeof(*ndopts)); 258 while (opt_len) { 259 int l; 260 if (opt_len < sizeof(struct nd_opt_hdr)) 261 return NULL; 262 l = nd_opt->nd_opt_len << 3; 263 if (opt_len < l || l == 0) 264 return NULL; 265 switch (nd_opt->nd_opt_type) { 266 case ND_OPT_SOURCE_LL_ADDR: 267 case ND_OPT_TARGET_LL_ADDR: 268 case ND_OPT_MTU: 269 case ND_OPT_REDIRECT_HDR: 270 if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) { 271 ND_PRINTK2(KERN_WARNING 272 "%s(): duplicated ND6 option found: type=%d\n", 273 __FUNCTION__, 274 nd_opt->nd_opt_type); 275 } else { 276 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 277 } 278 break; 279 case ND_OPT_PREFIX_INFO: 280 ndopts->nd_opts_pi_end = nd_opt; 281 if (!ndopts->nd_opt_array[nd_opt->nd_opt_type]) 282 ndopts->nd_opt_array[nd_opt->nd_opt_type] = nd_opt; 283 break; 284#ifdef CONFIG_IPV6_ROUTE_INFO 285 case ND_OPT_ROUTE_INFO: 286 ndopts->nd_opts_ri_end = nd_opt; 287 if (!ndopts->nd_opts_ri) 288 ndopts->nd_opts_ri = nd_opt; 289 break; 290#endif 291 default: 292 if (ndisc_is_useropt(nd_opt)) { 293 ndopts->nd_useropts_end = nd_opt; 294 if (!ndopts->nd_useropts) 295 ndopts->nd_useropts = nd_opt; 296 } else { 297 /* 298 * Unknown options must be silently ignored, 299 * to accommodate future extension to the 300 * protocol. 301 */ 302 ND_PRINTK2(KERN_NOTICE 303 "%s(): ignored unsupported option; type=%d, len=%d\n", 304 __FUNCTION__, 305 nd_opt->nd_opt_type, nd_opt->nd_opt_len); 306 } 307 } 308 opt_len -= l; 309 nd_opt = ((void *)nd_opt) + l; 310 } 311 return ndopts; 312} 313 314static inline u8 *ndisc_opt_addr_data(struct nd_opt_hdr *p, 315 struct net_device *dev) 316{ 317 u8 *lladdr = (u8 *)(p + 1); 318 int lladdrlen = p->nd_opt_len << 3; 319 int prepad = ndisc_addr_option_pad(dev->type); 320 if (lladdrlen != NDISC_OPT_SPACE(dev->addr_len + prepad)) 321 return NULL; 322 return (lladdr + prepad); 323} 324 325int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int dir) 326{ 327 switch (dev->type) { 328 case ARPHRD_ETHER: 329 case ARPHRD_IEEE802: /* Not sure. Check it later. --ANK */ 330 case ARPHRD_FDDI: 331 ipv6_eth_mc_map(addr, buf); 332 return 0; 333 case ARPHRD_IEEE802_TR: 334 ipv6_tr_mc_map(addr,buf); 335 return 0; 336 case ARPHRD_ARCNET: 337 ipv6_arcnet_mc_map(addr, buf); 338 return 0; 339 case ARPHRD_INFINIBAND: 340 ipv6_ib_mc_map(addr, buf); 341 return 0; 342 default: 343 if (dir) { 344 memcpy(buf, dev->broadcast, dev->addr_len); 345 return 0; 346 } 347 } 348 return -EINVAL; 349} 350 351EXPORT_SYMBOL(ndisc_mc_map); 352 353static u32 ndisc_hash(const void *pkey, const struct net_device *dev) 354{ 355 const u32 *p32 = pkey; 356 u32 addr_hash, i; 357 358 addr_hash = 0; 359 for (i = 0; i < (sizeof(struct in6_addr) / sizeof(u32)); i++) 360 addr_hash ^= *p32++; 361 362 return jhash_2words(addr_hash, dev->ifindex, nd_tbl.hash_rnd); 363} 364 365static int ndisc_constructor(struct neighbour *neigh) 366{ 367 struct in6_addr *addr = (struct in6_addr*)&neigh->primary_key; 368 struct net_device *dev = neigh->dev; 369 struct inet6_dev *in6_dev; 370 struct neigh_parms *parms; 371 int is_multicast = ipv6_addr_is_multicast(addr); 372 373 rcu_read_lock(); 374 in6_dev = in6_dev_get(dev); 375 if (in6_dev == NULL) { 376 rcu_read_unlock(); 377 return -EINVAL; 378 } 379 380 parms = in6_dev->nd_parms; 381 __neigh_parms_put(neigh->parms); 382 neigh->parms = neigh_parms_clone(parms); 383 rcu_read_unlock(); 384 385 neigh->type = is_multicast ? RTN_MULTICAST : RTN_UNICAST; 386 if (!dev->header_ops) { 387 neigh->nud_state = NUD_NOARP; 388 neigh->ops = &ndisc_direct_ops; 389 neigh->output = neigh->ops->queue_xmit; 390 } else { 391 if (is_multicast) { 392 neigh->nud_state = NUD_NOARP; 393 ndisc_mc_map(addr, neigh->ha, dev, 1); 394 } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { 395 neigh->nud_state = NUD_NOARP; 396 memcpy(neigh->ha, dev->dev_addr, dev->addr_len); 397 if (dev->flags&IFF_LOOPBACK) 398 neigh->type = RTN_LOCAL; 399 } else if (dev->flags&IFF_POINTOPOINT) { 400 neigh->nud_state = NUD_NOARP; 401 memcpy(neigh->ha, dev->broadcast, dev->addr_len); 402 } 403 if (dev->header_ops->cache) 404 neigh->ops = &ndisc_hh_ops; 405 else 406 neigh->ops = &ndisc_generic_ops; 407 if (neigh->nud_state&NUD_VALID) 408 neigh->output = neigh->ops->connected_output; 409 else 410 neigh->output = neigh->ops->output; 411 } 412 in6_dev_put(in6_dev); 413 return 0; 414} 415 416static int pndisc_constructor(struct pneigh_entry *n) 417{ 418 struct in6_addr *addr = (struct in6_addr*)&n->key; 419 struct in6_addr maddr; 420 struct net_device *dev = n->dev; 421 422 if (dev == NULL || __in6_dev_get(dev) == NULL) 423 return -EINVAL; 424 addrconf_addr_solict_mult(addr, &maddr); 425 ipv6_dev_mc_inc(dev, &maddr); 426 return 0; 427} 428 429static void pndisc_destructor(struct pneigh_entry *n) 430{ 431 struct in6_addr *addr = (struct in6_addr*)&n->key; 432 struct in6_addr maddr; 433 struct net_device *dev = n->dev; 434 435 if (dev == NULL || __in6_dev_get(dev) == NULL) 436 return; 437 addrconf_addr_solict_mult(addr, &maddr); 438 ipv6_dev_mc_dec(dev, &maddr); 439} 440 441/* 442 * Send a Neighbour Advertisement 443 */ 444 445static inline void ndisc_flow_init(struct flowi *fl, u8 type, 446 struct in6_addr *saddr, struct in6_addr *daddr, 447 int oif) 448{ 449 memset(fl, 0, sizeof(*fl)); 450 ipv6_addr_copy(&fl->fl6_src, saddr); 451 ipv6_addr_copy(&fl->fl6_dst, daddr); 452 fl->proto = IPPROTO_ICMPV6; 453 fl->fl_icmp_type = type; 454 fl->fl_icmp_code = 0; 455 fl->oif = oif; 456 security_sk_classify_flow(ndisc_socket->sk, fl); 457} 458 459static void __ndisc_send(struct net_device *dev, 460 struct neighbour *neigh, 461 struct in6_addr *daddr, struct in6_addr *saddr, 462 struct icmp6hdr *icmp6h, struct in6_addr *target, 463 int llinfo) 464{ 465 struct flowi fl; 466 struct dst_entry *dst; 467 struct sock *sk = ndisc_socket->sk; 468 struct sk_buff *skb; 469 struct icmp6hdr *hdr; 470 struct inet6_dev *idev; 471 int len; 472 int err; 473 u8 *opt, type; 474 475 type = icmp6h->icmp6_type; 476 477 ndisc_flow_init(&fl, type, saddr, daddr, 478 dev->ifindex); 479 480 dst = ndisc_dst_alloc(dev, neigh, daddr, ip6_output); 481 if (!dst) 482 return; 483 484 err = xfrm_lookup(&dst, &fl, NULL, 0); 485 if (err < 0) 486 return; 487 488 if (!dev->addr_len) 489 llinfo = 0; 490 491 len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0); 492 if (llinfo) 493 len += ndisc_opt_addr_space(dev); 494 495 skb = sock_alloc_send_skb(sk, 496 (MAX_HEADER + sizeof(struct ipv6hdr) + 497 len + LL_RESERVED_SPACE(dev)), 498 1, &err); 499 if (!skb) { 500 ND_PRINTK0(KERN_ERR 501 "ICMPv6 ND: %s() failed to allocate an skb.\n", 502 __FUNCTION__); 503 dst_release(dst); 504 return; 505 } 506 507 skb_reserve(skb, LL_RESERVED_SPACE(dev)); 508 ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len); 509 510 skb->transport_header = skb->tail; 511 skb_put(skb, len); 512 513 hdr = (struct icmp6hdr *)skb_transport_header(skb); 514 memcpy(hdr, icmp6h, sizeof(*hdr)); 515 516 opt = skb_transport_header(skb) + sizeof(struct icmp6hdr); 517 if (target) { 518 ipv6_addr_copy((struct in6_addr *)opt, target); 519 opt += sizeof(*target); 520 } 521 522 if (llinfo) 523 ndisc_fill_addr_option(opt, llinfo, dev->dev_addr, 524 dev->addr_len, dev->type); 525 526 hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len, 527 IPPROTO_ICMPV6, 528 csum_partial((__u8 *) hdr, 529 len, 0)); 530 531 skb->dst = dst; 532 533 idev = in6_dev_get(dst->dev); 534 IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS); 535 536 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, dst_output); 537 if (!err) { 538 ICMP6MSGOUT_INC_STATS(idev, type); 539 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS); 540 } 541 542 if (likely(idev != NULL)) 543 in6_dev_put(idev); 544} 545 546static void ndisc_send_na(struct net_device *dev, struct neighbour *neigh, 547 struct in6_addr *daddr, struct in6_addr *solicited_addr, 548 int router, int solicited, int override, int inc_opt) 549{ 550 struct in6_addr tmpaddr; 551 struct inet6_ifaddr *ifp; 552 struct in6_addr *src_addr; 553 struct icmp6hdr icmp6h = { 554 .icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT, 555 }; 556 557 /* for anycast or proxy, solicited_addr != src_addr */ 558 ifp = ipv6_get_ifaddr(solicited_addr, dev, 1); 559 if (ifp) { 560 src_addr = solicited_addr; 561 if (ifp->flags & IFA_F_OPTIMISTIC) 562 override = 0; 563 in6_ifa_put(ifp); 564 } else { 565 if (ipv6_dev_get_saddr(dev, daddr, &tmpaddr)) 566 return; 567 src_addr = &tmpaddr; 568 } 569 570 icmp6h.icmp6_router = router; 571 icmp6h.icmp6_solicited = solicited; 572 icmp6h.icmp6_override = override; 573 574 __ndisc_send(dev, neigh, daddr, src_addr, 575 &icmp6h, solicited_addr, 576 inc_opt ? ND_OPT_TARGET_LL_ADDR : 0); 577} 578 579void ndisc_send_ns(struct net_device *dev, struct neighbour *neigh, 580 struct in6_addr *solicit, 581 struct in6_addr *daddr, struct in6_addr *saddr) 582{ 583 struct in6_addr addr_buf; 584 struct icmp6hdr icmp6h = { 585 .icmp6_type = NDISC_NEIGHBOUR_SOLICITATION, 586 }; 587 588 if (saddr == NULL) { 589 if (ipv6_get_lladdr(dev, &addr_buf, 590 (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC))) 591 return; 592 saddr = &addr_buf; 593 } 594 595 __ndisc_send(dev, neigh, daddr, saddr, 596 &icmp6h, solicit, 597 !ipv6_addr_any(saddr) ? ND_OPT_SOURCE_LL_ADDR : 0); 598} 599 600void ndisc_send_rs(struct net_device *dev, struct in6_addr *saddr, 601 struct in6_addr *daddr) 602{ 603 struct icmp6hdr icmp6h = { 604 .icmp6_type = NDISC_ROUTER_SOLICITATION, 605 }; 606 int send_sllao = dev->addr_len; 607 608#ifdef CONFIG_IPV6_OPTIMISTIC_DAD 609 /* 610 * According to section 2.2 of RFC 4429, we must not 611 * send router solicitations with a sllao from 612 * optimistic addresses, but we may send the solicitation 613 * if we don't include the sllao. So here we check 614 * if our address is optimistic, and if so, we 615 * suppress the inclusion of the sllao. 616 */ 617 if (send_sllao) { 618 struct inet6_ifaddr *ifp = ipv6_get_ifaddr(saddr, dev, 1); 619 if (ifp) { 620 if (ifp->flags & IFA_F_OPTIMISTIC) { 621 send_sllao = 0; 622 } 623 in6_ifa_put(ifp); 624 } else { 625 send_sllao = 0; 626 } 627 } 628#endif 629 __ndisc_send(dev, NULL, daddr, saddr, 630 &icmp6h, NULL, 631 send_sllao ? ND_OPT_SOURCE_LL_ADDR : 0); 632} 633 634 635static void ndisc_error_report(struct neighbour *neigh, struct sk_buff *skb) 636{ 637 /* 638 * "The sender MUST return an ICMP 639 * destination unreachable" 640 */ 641 dst_link_failure(skb); 642 kfree_skb(skb); 643} 644 645/* Called with locked neigh: either read or both */ 646 647static void ndisc_solicit(struct neighbour *neigh, struct sk_buff *skb) 648{ 649 struct in6_addr *saddr = NULL; 650 struct in6_addr mcaddr; 651 struct net_device *dev = neigh->dev; 652 struct in6_addr *target = (struct in6_addr *)&neigh->primary_key; 653 int probes = atomic_read(&neigh->probes); 654 655 if (skb && ipv6_chk_addr(&ipv6_hdr(skb)->saddr, dev, 1)) 656 saddr = &ipv6_hdr(skb)->saddr; 657 658 if ((probes -= neigh->parms->ucast_probes) < 0) { 659 if (!(neigh->nud_state & NUD_VALID)) { 660 ND_PRINTK1(KERN_DEBUG 661 "%s(): trying to ucast probe in NUD_INVALID: " 662 NIP6_FMT "\n", 663 __FUNCTION__, 664 NIP6(*target)); 665 } 666 ndisc_send_ns(dev, neigh, target, target, saddr); 667 } else if ((probes -= neigh->parms->app_probes) < 0) { 668#ifdef CONFIG_ARPD 669 neigh_app_ns(neigh); 670#endif 671 } else { 672 addrconf_addr_solict_mult(target, &mcaddr); 673 ndisc_send_ns(dev, NULL, target, &mcaddr, saddr); 674 } 675} 676 677static void ndisc_recv_ns(struct sk_buff *skb) 678{ 679 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 680 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 681 struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 682 u8 *lladdr = NULL; 683 u32 ndoptlen = skb->tail - (skb->transport_header + 684 offsetof(struct nd_msg, opt)); 685 struct ndisc_options ndopts; 686 struct net_device *dev = skb->dev; 687 struct inet6_ifaddr *ifp; 688 struct inet6_dev *idev = NULL; 689 struct neighbour *neigh; 690 struct pneigh_entry *pneigh = NULL; 691 int dad = ipv6_addr_any(saddr); 692 int inc; 693 int is_router; 694 695 if (ipv6_addr_is_multicast(&msg->target)) { 696 ND_PRINTK2(KERN_WARNING 697 "ICMPv6 NS: multicast target address"); 698 return; 699 } 700 701 /* 702 * RFC2461 7.1.1: 703 * DAD has to be destined for solicited node multicast address. 704 */ 705 if (dad && 706 !(daddr->s6_addr32[0] == htonl(0xff020000) && 707 daddr->s6_addr32[1] == htonl(0x00000000) && 708 daddr->s6_addr32[2] == htonl(0x00000001) && 709 daddr->s6_addr [12] == 0xff )) { 710 ND_PRINTK2(KERN_WARNING 711 "ICMPv6 NS: bad DAD packet (wrong destination)\n"); 712 return; 713 } 714 715 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { 716 ND_PRINTK2(KERN_WARNING 717 "ICMPv6 NS: invalid ND options\n"); 718 return; 719 } 720 721 if (ndopts.nd_opts_src_lladdr) { 722 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, dev); 723 if (!lladdr) { 724 ND_PRINTK2(KERN_WARNING 725 "ICMPv6 NS: invalid link-layer address length\n"); 726 return; 727 } 728 729 /* RFC2461 7.1.1: 730 * If the IP source address is the unspecified address, 731 * there MUST NOT be source link-layer address option 732 * in the message. 733 */ 734 if (dad) { 735 ND_PRINTK2(KERN_WARNING 736 "ICMPv6 NS: bad DAD packet (link-layer address option)\n"); 737 return; 738 } 739 } 740 741 inc = ipv6_addr_is_multicast(daddr); 742 743 if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1)) != NULL) { 744 745 if (ifp->flags & (IFA_F_TENTATIVE|IFA_F_OPTIMISTIC)) { 746 if (dad) { 747 if (dev->type == ARPHRD_IEEE802_TR) { 748 const unsigned char *sadr; 749 sadr = skb_mac_header(skb); 750 if (((sadr[8] ^ dev->dev_addr[0]) & 0x7f) == 0 && 751 sadr[9] == dev->dev_addr[1] && 752 sadr[10] == dev->dev_addr[2] && 753 sadr[11] == dev->dev_addr[3] && 754 sadr[12] == dev->dev_addr[4] && 755 sadr[13] == dev->dev_addr[5]) { 756 /* looped-back to us */ 757 goto out; 758 } 759 } 760 761 /* 762 * We are colliding with another node 763 * who is doing DAD 764 * so fail our DAD process 765 */ 766 addrconf_dad_failure(ifp); 767 return; 768 } else { 769 /* 770 * This is not a dad solicitation. 771 * If we are an optimistic node, 772 * we should respond. 773 * Otherwise, we should ignore it. 774 */ 775 if (!(ifp->flags & IFA_F_OPTIMISTIC)) 776 goto out; 777 } 778 } 779 780 idev = ifp->idev; 781 } else { 782 idev = in6_dev_get(dev); 783 if (!idev) { 784 /* XXX: count this drop? */ 785 return; 786 } 787 788 if (ipv6_chk_acast_addr(dev, &msg->target) || 789 (idev->cnf.forwarding && 790 (ipv6_devconf.proxy_ndp || idev->cnf.proxy_ndp) && 791 (pneigh = pneigh_lookup(&nd_tbl, 792 &msg->target, dev, 0)) != NULL)) { 793 if (!(NEIGH_CB(skb)->flags & LOCALLY_ENQUEUED) && 794 skb->pkt_type != PACKET_HOST && 795 inc != 0 && 796 idev->nd_parms->proxy_delay != 0) { 797 /* 798 * for anycast or proxy, 799 * sender should delay its response 800 * by a random time between 0 and 801 * MAX_ANYCAST_DELAY_TIME seconds. 802 * (RFC2461) -- yoshfuji 803 */ 804 struct sk_buff *n = skb_clone(skb, GFP_ATOMIC); 805 if (n) 806 pneigh_enqueue(&nd_tbl, idev->nd_parms, n); 807 goto out; 808 } 809 } else 810 goto out; 811 } 812 813 is_router = !!(pneigh ? pneigh->flags & NTF_ROUTER : idev->cnf.forwarding); 814 815 if (dad) { 816 struct in6_addr maddr; 817 818 ipv6_addr_all_nodes(&maddr); 819 ndisc_send_na(dev, NULL, &maddr, &msg->target, 820 is_router, 0, (ifp != NULL), 1); 821 goto out; 822 } 823 824 if (inc) 825 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_mcast); 826 else 827 NEIGH_CACHE_STAT_INC(&nd_tbl, rcv_probes_ucast); 828 829 /* 830 * update / create cache entry 831 * for the source address 832 */ 833 neigh = __neigh_lookup(&nd_tbl, saddr, dev, 834 !inc || lladdr || !dev->addr_len); 835 if (neigh) 836 neigh_update(neigh, lladdr, NUD_STALE, 837 NEIGH_UPDATE_F_WEAK_OVERRIDE| 838 NEIGH_UPDATE_F_OVERRIDE); 839 if (neigh || !dev->header_ops) { 840 ndisc_send_na(dev, neigh, saddr, &msg->target, 841 is_router, 842 1, (ifp != NULL && inc), inc); 843 if (neigh) 844 neigh_release(neigh); 845 } 846 847out: 848 if (ifp) 849 in6_ifa_put(ifp); 850 else 851 in6_dev_put(idev); 852 853 return; 854} 855 856static void ndisc_recv_na(struct sk_buff *skb) 857{ 858 struct nd_msg *msg = (struct nd_msg *)skb_transport_header(skb); 859 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 860 struct in6_addr *daddr = &ipv6_hdr(skb)->daddr; 861 u8 *lladdr = NULL; 862 u32 ndoptlen = skb->tail - (skb->transport_header + 863 offsetof(struct nd_msg, opt)); 864 struct ndisc_options ndopts; 865 struct net_device *dev = skb->dev; 866 struct inet6_ifaddr *ifp; 867 struct neighbour *neigh; 868 869 if (skb->len < sizeof(struct nd_msg)) { 870 ND_PRINTK2(KERN_WARNING 871 "ICMPv6 NA: packet too short\n"); 872 return; 873 } 874 875 if (ipv6_addr_is_multicast(&msg->target)) { 876 ND_PRINTK2(KERN_WARNING 877 "ICMPv6 NA: target address is multicast.\n"); 878 return; 879 } 880 881 if (ipv6_addr_is_multicast(daddr) && 882 msg->icmph.icmp6_solicited) { 883 ND_PRINTK2(KERN_WARNING 884 "ICMPv6 NA: solicited NA is multicasted.\n"); 885 return; 886 } 887 888 if (!ndisc_parse_options(msg->opt, ndoptlen, &ndopts)) { 889 ND_PRINTK2(KERN_WARNING 890 "ICMPv6 NS: invalid ND option\n"); 891 return; 892 } 893 if (ndopts.nd_opts_tgt_lladdr) { 894 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, dev); 895 if (!lladdr) { 896 ND_PRINTK2(KERN_WARNING 897 "ICMPv6 NA: invalid link-layer address length\n"); 898 return; 899 } 900 } 901 if ((ifp = ipv6_get_ifaddr(&msg->target, dev, 1))) { 902 if (ifp->flags & IFA_F_TENTATIVE) { 903 addrconf_dad_failure(ifp); 904 return; 905 } 906 /* What should we make now? The advertisement 907 is invalid, but ndisc specs say nothing 908 about it. It could be misconfiguration, or 909 an smart proxy agent tries to help us :-) 910 */ 911 ND_PRINTK1(KERN_WARNING 912 "ICMPv6 NA: someone advertises our address on %s!\n", 913 ifp->idev->dev->name); 914 in6_ifa_put(ifp); 915 return; 916 } 917 neigh = neigh_lookup(&nd_tbl, &msg->target, dev); 918 919 if (neigh) { 920 u8 old_flags = neigh->flags; 921 922 if (neigh->nud_state & NUD_FAILED) 923 goto out; 924 925 /* 926 * Don't update the neighbor cache entry on a proxy NA from 927 * ourselves because either the proxied node is off link or it 928 * has already sent a NA to us. 929 */ 930 if (lladdr && !memcmp(lladdr, dev->dev_addr, dev->addr_len) && 931 ipv6_devconf.forwarding && ipv6_devconf.proxy_ndp && 932 pneigh_lookup(&nd_tbl, &msg->target, dev, 0)) { 933 /* XXX: idev->cnf.prixy_ndp */ 934 goto out; 935 } 936 937 neigh_update(neigh, lladdr, 938 msg->icmph.icmp6_solicited ? NUD_REACHABLE : NUD_STALE, 939 NEIGH_UPDATE_F_WEAK_OVERRIDE| 940 (msg->icmph.icmp6_override ? NEIGH_UPDATE_F_OVERRIDE : 0)| 941 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 942 (msg->icmph.icmp6_router ? NEIGH_UPDATE_F_ISROUTER : 0)); 943 944 if ((old_flags & ~neigh->flags) & NTF_ROUTER) { 945 /* 946 * Change: router to host 947 */ 948 struct rt6_info *rt; 949 rt = rt6_get_dflt_router(saddr, dev); 950 if (rt) 951 ip6_del_rt(rt); 952 } 953 954out: 955 neigh_release(neigh); 956 } 957} 958 959static void ndisc_recv_rs(struct sk_buff *skb) 960{ 961 struct rs_msg *rs_msg = (struct rs_msg *)skb_transport_header(skb); 962 unsigned long ndoptlen = skb->len - sizeof(*rs_msg); 963 struct neighbour *neigh; 964 struct inet6_dev *idev; 965 struct in6_addr *saddr = &ipv6_hdr(skb)->saddr; 966 struct ndisc_options ndopts; 967 u8 *lladdr = NULL; 968 969 if (skb->len < sizeof(*rs_msg)) 970 return; 971 972 idev = in6_dev_get(skb->dev); 973 if (!idev) { 974 if (net_ratelimit()) 975 ND_PRINTK1("ICMP6 RS: can't find in6 device\n"); 976 return; 977 } 978 979 /* Don't accept RS if we're not in router mode */ 980 if (!idev->cnf.forwarding) 981 goto out; 982 983 /* 984 * Don't update NCE if src = ::; 985 * this implies that the source node has no ip address assigned yet. 986 */ 987 if (ipv6_addr_any(saddr)) 988 goto out; 989 990 /* Parse ND options */ 991 if (!ndisc_parse_options(rs_msg->opt, ndoptlen, &ndopts)) { 992 if (net_ratelimit()) 993 ND_PRINTK2("ICMP6 NS: invalid ND option, ignored\n"); 994 goto out; 995 } 996 997 if (ndopts.nd_opts_src_lladdr) { 998 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 999 skb->dev); 1000 if (!lladdr) 1001 goto out; 1002 } 1003 1004 neigh = __neigh_lookup(&nd_tbl, saddr, skb->dev, 1); 1005 if (neigh) { 1006 neigh_update(neigh, lladdr, NUD_STALE, 1007 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1008 NEIGH_UPDATE_F_OVERRIDE| 1009 NEIGH_UPDATE_F_OVERRIDE_ISROUTER); 1010 neigh_release(neigh); 1011 } 1012out: 1013 in6_dev_put(idev); 1014} 1015 1016static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt) 1017{ 1018 struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra); 1019 struct sk_buff *skb; 1020 struct nlmsghdr *nlh; 1021 struct nduseroptmsg *ndmsg; 1022 int err; 1023 int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg) 1024 + (opt->nd_opt_len << 3)); 1025 size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr)); 1026 1027 skb = nlmsg_new(msg_size, GFP_ATOMIC); 1028 if (skb == NULL) { 1029 err = -ENOBUFS; 1030 goto errout; 1031 } 1032 1033 nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0); 1034 if (nlh == NULL) { 1035 goto nla_put_failure; 1036 } 1037 1038 ndmsg = nlmsg_data(nlh); 1039 ndmsg->nduseropt_family = AF_INET6; 1040 ndmsg->nduseropt_ifindex = ra->dev->ifindex; 1041 ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type; 1042 ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code; 1043 ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3; 1044 1045 memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3); 1046 1047 NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr), 1048 &ipv6_hdr(ra)->saddr); 1049 nlmsg_end(skb, nlh); 1050 1051 err = rtnl_notify(skb, 0, RTNLGRP_ND_USEROPT, NULL, GFP_ATOMIC); 1052 if (err < 0) 1053 goto errout; 1054 1055 return; 1056 1057nla_put_failure: 1058 nlmsg_free(skb); 1059 err = -EMSGSIZE; 1060errout: 1061 rtnl_set_sk_err(RTNLGRP_ND_USEROPT, err); 1062} 1063 1064static void ndisc_router_discovery(struct sk_buff *skb) 1065{ 1066 struct ra_msg *ra_msg = (struct ra_msg *)skb_transport_header(skb); 1067 struct neighbour *neigh = NULL; 1068 struct inet6_dev *in6_dev; 1069 struct rt6_info *rt = NULL; 1070 int lifetime; 1071 struct ndisc_options ndopts; 1072 int optlen; 1073 unsigned int pref = 0; 1074 1075 __u8 * opt = (__u8 *)(ra_msg + 1); 1076 1077 optlen = (skb->tail - skb->transport_header) - sizeof(struct ra_msg); 1078 1079 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1080 ND_PRINTK2(KERN_WARNING 1081 "ICMPv6 RA: source address is not link-local.\n"); 1082 return; 1083 } 1084 if (optlen < 0) { 1085 ND_PRINTK2(KERN_WARNING 1086 "ICMPv6 RA: packet too short\n"); 1087 return; 1088 } 1089 1090 /* 1091 * set the RA_RECV flag in the interface 1092 */ 1093 1094 in6_dev = in6_dev_get(skb->dev); 1095 if (in6_dev == NULL) { 1096 ND_PRINTK0(KERN_ERR 1097 "ICMPv6 RA: can't find inet6 device for %s.\n", 1098 skb->dev->name); 1099 return; 1100 } 1101 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_ra) { 1102 in6_dev_put(in6_dev); 1103 return; 1104 } 1105 1106 if (!ndisc_parse_options(opt, optlen, &ndopts)) { 1107 in6_dev_put(in6_dev); 1108 ND_PRINTK2(KERN_WARNING 1109 "ICMP6 RA: invalid ND options\n"); 1110 return; 1111 } 1112 1113 if (in6_dev->if_flags & IF_RS_SENT) { 1114 /* 1115 * flag that an RA was received after an RS was sent 1116 * out on this interface. 1117 */ 1118 in6_dev->if_flags |= IF_RA_RCVD; 1119 } 1120 1121 /* 1122 * Remember the managed/otherconf flags from most recently 1123 * received RA message (RFC 2462) -- yoshfuji 1124 */ 1125 in6_dev->if_flags = (in6_dev->if_flags & ~(IF_RA_MANAGED | 1126 IF_RA_OTHERCONF)) | 1127 (ra_msg->icmph.icmp6_addrconf_managed ? 1128 IF_RA_MANAGED : 0) | 1129 (ra_msg->icmph.icmp6_addrconf_other ? 1130 IF_RA_OTHERCONF : 0); 1131 1132 if (!in6_dev->cnf.accept_ra_defrtr) 1133 goto skip_defrtr; 1134 1135 lifetime = ntohs(ra_msg->icmph.icmp6_rt_lifetime); 1136 1137#ifdef CONFIG_IPV6_ROUTER_PREF 1138 pref = ra_msg->icmph.icmp6_router_pref; 1139 /* 10b is handled as if it were 00b (medium) */ 1140 if (pref == ICMPV6_ROUTER_PREF_INVALID || 1141 !in6_dev->cnf.accept_ra_rtr_pref) 1142 pref = ICMPV6_ROUTER_PREF_MEDIUM; 1143#endif 1144 1145 rt = rt6_get_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev); 1146 1147 if (rt) 1148 neigh = rt->rt6i_nexthop; 1149 1150 if (rt && lifetime == 0) { 1151 neigh_clone(neigh); 1152 ip6_del_rt(rt); 1153 rt = NULL; 1154 } 1155 1156 if (rt == NULL && lifetime) { 1157 ND_PRINTK3(KERN_DEBUG 1158 "ICMPv6 RA: adding default router.\n"); 1159 1160 rt = rt6_add_dflt_router(&ipv6_hdr(skb)->saddr, skb->dev, pref); 1161 if (rt == NULL) { 1162 ND_PRINTK0(KERN_ERR 1163 "ICMPv6 RA: %s() failed to add default route.\n", 1164 __FUNCTION__); 1165 in6_dev_put(in6_dev); 1166 return; 1167 } 1168 1169 neigh = rt->rt6i_nexthop; 1170 if (neigh == NULL) { 1171 ND_PRINTK0(KERN_ERR 1172 "ICMPv6 RA: %s() got default router without neighbour.\n", 1173 __FUNCTION__); 1174 dst_release(&rt->u.dst); 1175 in6_dev_put(in6_dev); 1176 return; 1177 } 1178 neigh->flags |= NTF_ROUTER; 1179 } else if (rt) { 1180 rt->rt6i_flags |= (rt->rt6i_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 1181 } 1182 1183 if (rt) 1184 rt->rt6i_expires = jiffies + (HZ * lifetime); 1185 1186 if (ra_msg->icmph.icmp6_hop_limit) { 1187 in6_dev->cnf.hop_limit = ra_msg->icmph.icmp6_hop_limit; 1188 if (rt) 1189 rt->u.dst.metrics[RTAX_HOPLIMIT-1] = ra_msg->icmph.icmp6_hop_limit; 1190 } 1191 1192skip_defrtr: 1193 1194 /* 1195 * Update Reachable Time and Retrans Timer 1196 */ 1197 1198 if (in6_dev->nd_parms) { 1199 unsigned long rtime = ntohl(ra_msg->retrans_timer); 1200 1201 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/HZ) { 1202 rtime = (rtime*HZ)/1000; 1203 if (rtime < HZ/10) 1204 rtime = HZ/10; 1205 in6_dev->nd_parms->retrans_time = rtime; 1206 in6_dev->tstamp = jiffies; 1207 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1208 } 1209 1210 rtime = ntohl(ra_msg->reachable_time); 1211 if (rtime && rtime/1000 < MAX_SCHEDULE_TIMEOUT/(3*HZ)) { 1212 rtime = (rtime*HZ)/1000; 1213 1214 if (rtime < HZ/10) 1215 rtime = HZ/10; 1216 1217 if (rtime != in6_dev->nd_parms->base_reachable_time) { 1218 in6_dev->nd_parms->base_reachable_time = rtime; 1219 in6_dev->nd_parms->gc_staletime = 3 * rtime; 1220 in6_dev->nd_parms->reachable_time = neigh_rand_reach_time(rtime); 1221 in6_dev->tstamp = jiffies; 1222 inet6_ifinfo_notify(RTM_NEWLINK, in6_dev); 1223 } 1224 } 1225 } 1226 1227 /* 1228 * Process options. 1229 */ 1230 1231 if (!neigh) 1232 neigh = __neigh_lookup(&nd_tbl, &ipv6_hdr(skb)->saddr, 1233 skb->dev, 1); 1234 if (neigh) { 1235 u8 *lladdr = NULL; 1236 if (ndopts.nd_opts_src_lladdr) { 1237 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_src_lladdr, 1238 skb->dev); 1239 if (!lladdr) { 1240 ND_PRINTK2(KERN_WARNING 1241 "ICMPv6 RA: invalid link-layer address length\n"); 1242 goto out; 1243 } 1244 } 1245 neigh_update(neigh, lladdr, NUD_STALE, 1246 NEIGH_UPDATE_F_WEAK_OVERRIDE| 1247 NEIGH_UPDATE_F_OVERRIDE| 1248 NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 1249 NEIGH_UPDATE_F_ISROUTER); 1250 } 1251 1252#ifdef CONFIG_IPV6_ROUTE_INFO 1253 if (in6_dev->cnf.accept_ra_rtr_pref && ndopts.nd_opts_ri) { 1254 struct nd_opt_hdr *p; 1255 for (p = ndopts.nd_opts_ri; 1256 p; 1257 p = ndisc_next_option(p, ndopts.nd_opts_ri_end)) { 1258 if (((struct route_info *)p)->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen) 1259 continue; 1260 rt6_route_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3, 1261 &ipv6_hdr(skb)->saddr); 1262 } 1263 } 1264#endif 1265 1266 if (in6_dev->cnf.accept_ra_pinfo && ndopts.nd_opts_pi) { 1267 struct nd_opt_hdr *p; 1268 for (p = ndopts.nd_opts_pi; 1269 p; 1270 p = ndisc_next_option(p, ndopts.nd_opts_pi_end)) { 1271 addrconf_prefix_rcv(skb->dev, (u8*)p, (p->nd_opt_len) << 3); 1272 } 1273 } 1274 1275 if (ndopts.nd_opts_mtu) { 1276 __be32 n; 1277 u32 mtu; 1278 1279 memcpy(&n, ((u8*)(ndopts.nd_opts_mtu+1))+2, sizeof(mtu)); 1280 mtu = ntohl(n); 1281 1282 if (mtu < IPV6_MIN_MTU || mtu > skb->dev->mtu) { 1283 ND_PRINTK2(KERN_WARNING 1284 "ICMPv6 RA: invalid mtu: %d\n", 1285 mtu); 1286 } else if (in6_dev->cnf.mtu6 != mtu) { 1287 in6_dev->cnf.mtu6 = mtu; 1288 1289 if (rt) 1290 rt->u.dst.metrics[RTAX_MTU-1] = mtu; 1291 1292 rt6_mtu_change(skb->dev, mtu); 1293 } 1294 } 1295 1296 if (ndopts.nd_useropts) { 1297 struct nd_opt_hdr *opt; 1298 for (opt = ndopts.nd_useropts; 1299 opt; 1300 opt = ndisc_next_useropt(opt, ndopts.nd_useropts_end)) { 1301 ndisc_ra_useropt(skb, opt); 1302 } 1303 } 1304 1305 if (ndopts.nd_opts_tgt_lladdr || ndopts.nd_opts_rh) { 1306 ND_PRINTK2(KERN_WARNING 1307 "ICMPv6 RA: invalid RA options"); 1308 } 1309out: 1310 if (rt) 1311 dst_release(&rt->u.dst); 1312 else if (neigh) 1313 neigh_release(neigh); 1314 in6_dev_put(in6_dev); 1315} 1316 1317static void ndisc_redirect_rcv(struct sk_buff *skb) 1318{ 1319 struct inet6_dev *in6_dev; 1320 struct icmp6hdr *icmph; 1321 struct in6_addr *dest; 1322 struct in6_addr *target; /* new first hop to destination */ 1323 struct neighbour *neigh; 1324 int on_link = 0; 1325 struct ndisc_options ndopts; 1326 int optlen; 1327 u8 *lladdr = NULL; 1328 1329 if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL)) { 1330 ND_PRINTK2(KERN_WARNING 1331 "ICMPv6 Redirect: source address is not link-local.\n"); 1332 return; 1333 } 1334 1335 optlen = skb->tail - skb->transport_header; 1336 optlen -= sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); 1337 1338 if (optlen < 0) { 1339 ND_PRINTK2(KERN_WARNING 1340 "ICMPv6 Redirect: packet too short\n"); 1341 return; 1342 } 1343 1344 icmph = icmp6_hdr(skb); 1345 target = (struct in6_addr *) (icmph + 1); 1346 dest = target + 1; 1347 1348 if (ipv6_addr_is_multicast(dest)) { 1349 ND_PRINTK2(KERN_WARNING 1350 "ICMPv6 Redirect: destination address is multicast.\n"); 1351 return; 1352 } 1353 1354 if (ipv6_addr_equal(dest, target)) { 1355 on_link = 1; 1356 } else if (ipv6_addr_type(target) != 1357 (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1358 ND_PRINTK2(KERN_WARNING 1359 "ICMPv6 Redirect: target address is not link-local unicast.\n"); 1360 return; 1361 } 1362 1363 in6_dev = in6_dev_get(skb->dev); 1364 if (!in6_dev) 1365 return; 1366 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) { 1367 in6_dev_put(in6_dev); 1368 return; 1369 } 1370 1371 /* RFC2461 8.1: 1372 * The IP source address of the Redirect MUST be the same as the current 1373 * first-hop router for the specified ICMP Destination Address. 1374 */ 1375 1376 if (!ndisc_parse_options((u8*)(dest + 1), optlen, &ndopts)) { 1377 ND_PRINTK2(KERN_WARNING 1378 "ICMPv6 Redirect: invalid ND options\n"); 1379 in6_dev_put(in6_dev); 1380 return; 1381 } 1382 if (ndopts.nd_opts_tgt_lladdr) { 1383 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, 1384 skb->dev); 1385 if (!lladdr) { 1386 ND_PRINTK2(KERN_WARNING 1387 "ICMPv6 Redirect: invalid link-layer address length\n"); 1388 in6_dev_put(in6_dev); 1389 return; 1390 } 1391 } 1392 1393 neigh = __neigh_lookup(&nd_tbl, target, skb->dev, 1); 1394 if (neigh) { 1395 rt6_redirect(dest, &ipv6_hdr(skb)->daddr, 1396 &ipv6_hdr(skb)->saddr, neigh, lladdr, 1397 on_link); 1398 neigh_release(neigh); 1399 } 1400 in6_dev_put(in6_dev); 1401} 1402 1403void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh, 1404 struct in6_addr *target) 1405{ 1406 struct sock *sk = ndisc_socket->sk; 1407 int len = sizeof(struct icmp6hdr) + 2 * sizeof(struct in6_addr); 1408 struct sk_buff *buff; 1409 struct icmp6hdr *icmph; 1410 struct in6_addr saddr_buf; 1411 struct in6_addr *addrp; 1412 struct net_device *dev; 1413 struct rt6_info *rt; 1414 struct dst_entry *dst; 1415 struct inet6_dev *idev; 1416 struct flowi fl; 1417 u8 *opt; 1418 int rd_len; 1419 int err; 1420 int hlen; 1421 u8 ha_buf[MAX_ADDR_LEN], *ha = NULL; 1422 1423 dev = skb->dev; 1424 1425 if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) { 1426 ND_PRINTK2(KERN_WARNING 1427 "ICMPv6 Redirect: no link-local address on %s\n", 1428 dev->name); 1429 return; 1430 } 1431 1432 if (!ipv6_addr_equal(&ipv6_hdr(skb)->daddr, target) && 1433 ipv6_addr_type(target) != (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 1434 ND_PRINTK2(KERN_WARNING 1435 "ICMPv6 Redirect: target address is not link-local unicast.\n"); 1436 return; 1437 } 1438 1439 ndisc_flow_init(&fl, NDISC_REDIRECT, &saddr_buf, &ipv6_hdr(skb)->saddr, 1440 dev->ifindex); 1441 1442 dst = ip6_route_output(NULL, &fl); 1443 if (dst == NULL) 1444 return; 1445 1446 err = xfrm_lookup(&dst, &fl, NULL, 0); 1447 if (err) 1448 return; 1449 1450 rt = (struct rt6_info *) dst; 1451 1452 if (rt->rt6i_flags & RTF_GATEWAY) { 1453 ND_PRINTK2(KERN_WARNING 1454 "ICMPv6 Redirect: destination is not a neighbour.\n"); 1455 dst_release(dst); 1456 return; 1457 } 1458 if (!xrlim_allow(dst, 1*HZ)) { 1459 dst_release(dst); 1460 return; 1461 } 1462 1463 if (dev->addr_len) { 1464 read_lock_bh(&neigh->lock); 1465 if (neigh->nud_state & NUD_VALID) { 1466 memcpy(ha_buf, neigh->ha, dev->addr_len); 1467 read_unlock_bh(&neigh->lock); 1468 ha = ha_buf; 1469 len += ndisc_opt_addr_space(dev); 1470 } else 1471 read_unlock_bh(&neigh->lock); 1472 } 1473 1474 rd_len = min_t(unsigned int, 1475 IPV6_MIN_MTU-sizeof(struct ipv6hdr)-len, skb->len + 8); 1476 rd_len &= ~0x7; 1477 len += rd_len; 1478 1479 buff = sock_alloc_send_skb(sk, 1480 (MAX_HEADER + sizeof(struct ipv6hdr) + 1481 len + LL_RESERVED_SPACE(dev)), 1482 1, &err); 1483 if (buff == NULL) { 1484 ND_PRINTK0(KERN_ERR 1485 "ICMPv6 Redirect: %s() failed to allocate an skb.\n", 1486 __FUNCTION__); 1487 dst_release(dst); 1488 return; 1489 } 1490 1491 hlen = 0; 1492 1493 skb_reserve(buff, LL_RESERVED_SPACE(dev)); 1494 ip6_nd_hdr(sk, buff, dev, &saddr_buf, &ipv6_hdr(skb)->saddr, 1495 IPPROTO_ICMPV6, len); 1496 1497 skb_set_transport_header(buff, skb_tail_pointer(buff) - buff->data); 1498 skb_put(buff, len); 1499 icmph = icmp6_hdr(buff); 1500 1501 memset(icmph, 0, sizeof(struct icmp6hdr)); 1502 icmph->icmp6_type = NDISC_REDIRECT; 1503 1504 /* 1505 * copy target and destination addresses 1506 */ 1507 1508 addrp = (struct in6_addr *)(icmph + 1); 1509 ipv6_addr_copy(addrp, target); 1510 addrp++; 1511 ipv6_addr_copy(addrp, &ipv6_hdr(skb)->daddr); 1512 1513 opt = (u8*) (addrp + 1); 1514 1515 /* 1516 * include target_address option 1517 */ 1518 1519 if (ha) 1520 opt = ndisc_fill_addr_option(opt, ND_OPT_TARGET_LL_ADDR, ha, 1521 dev->addr_len, dev->type); 1522 1523 /* 1524 * build redirect option and copy skb over to the new packet. 1525 */ 1526 1527 memset(opt, 0, 8); 1528 *(opt++) = ND_OPT_REDIRECT_HDR; 1529 *(opt++) = (rd_len >> 3); 1530 opt += 6; 1531 1532 memcpy(opt, ipv6_hdr(skb), rd_len - 8); 1533 1534 icmph->icmp6_cksum = csum_ipv6_magic(&saddr_buf, &ipv6_hdr(skb)->saddr, 1535 len, IPPROTO_ICMPV6, 1536 csum_partial((u8 *) icmph, len, 0)); 1537 1538 buff->dst = dst; 1539 idev = in6_dev_get(dst->dev); 1540 IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS); 1541 err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, buff, NULL, dst->dev, dst_output); 1542 if (!err) { 1543 ICMP6MSGOUT_INC_STATS(idev, NDISC_REDIRECT); 1544 ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS); 1545 } 1546 1547 if (likely(idev != NULL)) 1548 in6_dev_put(idev); 1549} 1550 1551static void pndisc_redo(struct sk_buff *skb) 1552{ 1553 ndisc_recv_ns(skb); 1554 kfree_skb(skb); 1555} 1556 1557int ndisc_rcv(struct sk_buff *skb) 1558{ 1559 struct nd_msg *msg; 1560 1561 if (!pskb_may_pull(skb, skb->len)) 1562 return 0; 1563 1564 msg = (struct nd_msg *)skb_transport_header(skb); 1565 1566 __skb_push(skb, skb->data - skb_transport_header(skb)); 1567 1568 if (ipv6_hdr(skb)->hop_limit != 255) { 1569 ND_PRINTK2(KERN_WARNING 1570 "ICMPv6 NDISC: invalid hop-limit: %d\n", 1571 ipv6_hdr(skb)->hop_limit); 1572 return 0; 1573 } 1574 1575 if (msg->icmph.icmp6_code != 0) { 1576 ND_PRINTK2(KERN_WARNING 1577 "ICMPv6 NDISC: invalid ICMPv6 code: %d\n", 1578 msg->icmph.icmp6_code); 1579 return 0; 1580 } 1581 1582 memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); 1583 1584 switch (msg->icmph.icmp6_type) { 1585 case NDISC_NEIGHBOUR_SOLICITATION: 1586 ndisc_recv_ns(skb); 1587 break; 1588 1589 case NDISC_NEIGHBOUR_ADVERTISEMENT: 1590 ndisc_recv_na(skb); 1591 break; 1592 1593 case NDISC_ROUTER_SOLICITATION: 1594 ndisc_recv_rs(skb); 1595 break; 1596 1597 case NDISC_ROUTER_ADVERTISEMENT: 1598 ndisc_router_discovery(skb); 1599 break; 1600 1601 case NDISC_REDIRECT: 1602 ndisc_redirect_rcv(skb); 1603 break; 1604 } 1605 1606 return 0; 1607} 1608 1609static int ndisc_netdev_event(struct notifier_block *this, unsigned long event, void *ptr) 1610{ 1611 struct net_device *dev = ptr; 1612 1613 if (dev->nd_net != &init_net) 1614 return NOTIFY_DONE; 1615 1616 switch (event) { 1617 case NETDEV_CHANGEADDR: 1618 neigh_changeaddr(&nd_tbl, dev); 1619 fib6_run_gc(~0UL); 1620 break; 1621 case NETDEV_DOWN: 1622 neigh_ifdown(&nd_tbl, dev); 1623 fib6_run_gc(~0UL); 1624 break; 1625 default: 1626 break; 1627 } 1628 1629 return NOTIFY_DONE; 1630} 1631 1632static struct notifier_block ndisc_netdev_notifier = { 1633 .notifier_call = ndisc_netdev_event, 1634}; 1635 1636#ifdef CONFIG_SYSCTL 1637static void ndisc_warn_deprecated_sysctl(struct ctl_table *ctl, 1638 const char *func, const char *dev_name) 1639{ 1640 static char warncomm[TASK_COMM_LEN]; 1641 static int warned; 1642 if (strcmp(warncomm, current->comm) && warned < 5) { 1643 strcpy(warncomm, current->comm); 1644 printk(KERN_WARNING 1645 "process `%s' is using deprecated sysctl (%s) " 1646 "net.ipv6.neigh.%s.%s; " 1647 "Use net.ipv6.neigh.%s.%s_ms " 1648 "instead.\n", 1649 warncomm, func, 1650 dev_name, ctl->procname, 1651 dev_name, ctl->procname); 1652 warned++; 1653 } 1654} 1655 1656int ndisc_ifinfo_sysctl_change(struct ctl_table *ctl, int write, struct file * filp, void __user *buffer, size_t *lenp, loff_t *ppos) 1657{ 1658 struct net_device *dev = ctl->extra1; 1659 struct inet6_dev *idev; 1660 int ret; 1661 1662 if ((strcmp(ctl->procname, "retrans_time") == 0) || 1663 (strcmp(ctl->procname, "base_reachable_time") == 0)) 1664 ndisc_warn_deprecated_sysctl(ctl, "syscall", dev ? dev->name : "default"); 1665 1666 if (strcmp(ctl->procname, "retrans_time") == 0) 1667 ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos); 1668 1669 else if (strcmp(ctl->procname, "base_reachable_time") == 0) 1670 ret = proc_dointvec_jiffies(ctl, write, 1671 filp, buffer, lenp, ppos); 1672 1673 else if ((strcmp(ctl->procname, "retrans_time_ms") == 0) || 1674 (strcmp(ctl->procname, "base_reachable_time_ms") == 0)) 1675 ret = proc_dointvec_ms_jiffies(ctl, write, 1676 filp, buffer, lenp, ppos); 1677 else 1678 ret = -1; 1679 1680 if (write && ret == 0 && dev && (idev = in6_dev_get(dev)) != NULL) { 1681 if (ctl->data == &idev->nd_parms->base_reachable_time) 1682 idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time); 1683 idev->tstamp = jiffies; 1684 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1685 in6_dev_put(idev); 1686 } 1687 return ret; 1688} 1689 1690static int ndisc_ifinfo_sysctl_strategy(ctl_table *ctl, int __user *name, 1691 int nlen, void __user *oldval, 1692 size_t __user *oldlenp, 1693 void __user *newval, size_t newlen) 1694{ 1695 struct net_device *dev = ctl->extra1; 1696 struct inet6_dev *idev; 1697 int ret; 1698 1699 if (ctl->ctl_name == NET_NEIGH_RETRANS_TIME || 1700 ctl->ctl_name == NET_NEIGH_REACHABLE_TIME) 1701 ndisc_warn_deprecated_sysctl(ctl, "procfs", dev ? dev->name : "default"); 1702 1703 switch (ctl->ctl_name) { 1704 case NET_NEIGH_REACHABLE_TIME: 1705 ret = sysctl_jiffies(ctl, name, nlen, 1706 oldval, oldlenp, newval, newlen); 1707 break; 1708 case NET_NEIGH_RETRANS_TIME_MS: 1709 case NET_NEIGH_REACHABLE_TIME_MS: 1710 ret = sysctl_ms_jiffies(ctl, name, nlen, 1711 oldval, oldlenp, newval, newlen); 1712 break; 1713 default: 1714 ret = 0; 1715 } 1716 1717 if (newval && newlen && ret > 0 && 1718 dev && (idev = in6_dev_get(dev)) != NULL) { 1719 if (ctl->ctl_name == NET_NEIGH_REACHABLE_TIME || 1720 ctl->ctl_name == NET_NEIGH_REACHABLE_TIME_MS) 1721 idev->nd_parms->reachable_time = neigh_rand_reach_time(idev->nd_parms->base_reachable_time); 1722 idev->tstamp = jiffies; 1723 inet6_ifinfo_notify(RTM_NEWLINK, idev); 1724 in6_dev_put(idev); 1725 } 1726 1727 return ret; 1728} 1729 1730#endif 1731 1732int __init ndisc_init(struct net_proto_family *ops) 1733{ 1734 struct ipv6_pinfo *np; 1735 struct sock *sk; 1736 int err; 1737 1738 err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_ICMPV6, &ndisc_socket); 1739 if (err < 0) { 1740 ND_PRINTK0(KERN_ERR 1741 "ICMPv6 NDISC: Failed to initialize the control socket (err %d).\n", 1742 err); 1743 ndisc_socket = NULL; /* For safety. */ 1744 return err; 1745 } 1746 1747 sk = ndisc_socket->sk; 1748 np = inet6_sk(sk); 1749 sk->sk_allocation = GFP_ATOMIC; 1750 np->hop_limit = 255; 1751 /* Do not loopback ndisc messages */ 1752 np->mc_loop = 0; 1753 sk->sk_prot->unhash(sk); 1754 1755 /* 1756 * Initialize the neighbour table 1757 */ 1758 1759 neigh_table_init(&nd_tbl); 1760 1761#ifdef CONFIG_SYSCTL 1762 neigh_sysctl_register(NULL, &nd_tbl.parms, NET_IPV6, NET_IPV6_NEIGH, 1763 "ipv6", 1764 &ndisc_ifinfo_sysctl_change, 1765 &ndisc_ifinfo_sysctl_strategy); 1766#endif 1767 1768 register_netdevice_notifier(&ndisc_netdev_notifier); 1769 return 0; 1770} 1771 1772void ndisc_cleanup(void) 1773{ 1774 unregister_netdevice_notifier(&ndisc_netdev_notifier); 1775#ifdef CONFIG_SYSCTL 1776 neigh_sysctl_unregister(&nd_tbl.parms); 1777#endif 1778 neigh_table_clear(&nd_tbl); 1779 sock_release(ndisc_socket); 1780 ndisc_socket = NULL; /* For safety. */ 1781} 1782